Method of making cellular concrete



Jan. 1, 1935'. J, A. RICE' METHOD 0E MAKING CELLULAR CONCRETE 2 Sheets-Sheet l Filed oct. 26, -1926 Ill IIUIIHHIM lvl v Il| ATTORNEY Jan. 1, 1935. .1. A. RICE METHOD OF MAKING CELLULAR CONCRETE Filed oct. 26, 1926 2 Sheets-Sheet 2 4.0.44 QON.

ATTORNEY Patented Jan. 1935 v METHOD oF sNTfnri John A. Rice, Berkeley, Califfassignor to The 'Bubblestone Company, Pittsburgh, Pa., Lancorporation olf Pennsylvania o A Application october 2c, 19264,seria1No; 144,392

:s claims, `(ci. 106424) My invention relates to a method of making cel-A lular concrete bymixing cement and sand or other fine aggregate andV charging or lling the same with minute rair cells; thus increasing the bulk thereofpwithout `materially'addingv to its weight.'

' For` this purpose I mix suitable-proportions of cement, sand and Water, thus forming a'tliin slurry or liquid mortar to which' I add a proper amount of `foam compound."V Thismixture is then placed in a suitable mixing machine, the function of `which is to force, by agitation, the minute air bubbles .into themortar, thereby increasing the bulkuntil the mixture has the desired weight for unit of volume of' the required specific gravity. f' v The-completed mixture is thereupon transferred to suitable molds and allowed'toset and jharden. It is practically immaterial what kind ofjalkaf line cement is used, and variouskinds, such-as PortlandVcemenufaluminous cements, such as limnite and gypsum cements, iare;eduallyjsuit-I able.`" The compound whichfi'sfin'troduced "into the mix for the purpose'of obtainingfafoaming con#V i by weight Casein, nely graduated a- 100 Water 500 i Calcium hydrate i 25 Benzoio acid 7 Beta naphthol 1 Arsenious acid (As203) 1 'I'he casein (nely graduated), the water, and the arsenious acid are first mixed until the casein is soaked and in homogeneous suspension; second the calcium hydrate is then added under gentle stirring until the casein is completely dissolved, whereupon this mixture is set aside Vfor from fifteen (l5) to twenty (20) days, oriuntil peptization is complete. Third, ingredients benzoic acid and beta naphthol are now added to the mixture either dry or suspended in a small amount of water. As soon as the benzoic acid and beta naphthol have been dissolved the compound is ready for use as already described.

In the accompanying drawingsha-s been illustrated a suitable mixing machine for forcing the air or gas into the slurry.

Figure 1 is a side elevation partly` in section of the mixing machine;

Figure 2, a section along line 2 2 of Figure 1;

Figure 3, a similar section, showing the'preferred blade construction; and

Figure 4, a. fragmentary detail of a blade in larger scale. o

In the drawingsreference numeral l0 represents a vessel or container of substantially cylindrical shape with its axis preferably horizontal,

50 as shown. Both its ends are closed by walls l1 y varied between wide margins.

and `l2and its'top side open, as at 13,when the mixing machine is in its normaler` operating position, as shown in'iuil lines on the drawings, the opening terminating with a lip 14'to 'facilitate discharge of the container when in tilted position as indicated by dot and dash unes: -By means of f ilanged' bushings 4or sleeves 15, 16,the containerl is mounted on a shaft 17 yfreely'revoluble therein. "'-At the left end'loi-the 'shaft a gear wheelV 18` in mesh with a pinion 19 is keyed or in any other manner secured thereto and a pulley 20 having an idler 2 141is'drive`n by'abelt from a motor not shownand in turn revolves-the shaft 17` and the gear wheel l8through the pinion 19. The sleeve orbushing 15 is mounted to revolve in a,A bearing 22 secured on Ythe base 23. The sleeve 16 atthe other end ofthe sha-ft is rigidly secured in the-hub 24 ofthe spur gear 25 and mounted torevolvein the bearing 26 also secured to the fbase 23;* In this'vm'anner the containercan be tilted independent of vthe lshaft 17 through the intermediary of the-spur gear when yactuated. from the crank handle 27 through the pinion 28.

Upon the shaft 17 are `rigidly'secured by means whichbladelhas right-hand pitch'and 32 lefthand pitch. Accordinglyioounter currents are set up in the contents of the vessel, both running fromthe end walls 11, 12 towards the middle of the container or Vessel 10, when the shaft 17 with .Y

the blades 31, 32 is revolved. The helical blades may be made from 'coarse screen wire or expanded metal 132, as shown in Figures 3 and 4, or

from sheet metal, as in Figure 2, or any other` ture or"slurry should contain a sufficient amount of water to make it thin enough to run from a spoon. ATo this slurry in the container is then added the already described foam compound to the amount of one percentum of the cement used. This is the preferred proportion, but it may be The foam compound may be added to the slurry after the latter has been prepared, but is preferably poured into the water from which the slurry is prepared.

When the container has been charged with slurry and foam compound as now described, the shaft 17 with the helical blades is set in motion by starting the motor. The peripheral speed of the blades should be approximately fifty feet per minute, but a wide variation is permissible. The helical blades 31, 32 or 132 will then drag bubbles from the foarny compound V`below the .surface 33 into the .slurry #Gradually the .volume of cement mix will 'thenincreasa due to the accumulation of entrapped air. As soon as the mixture has .be-

come of the desired specific gravity the operation is stopped and the mixture iis discharged.

from the container by turning the, crank handle 2'7 to tilt it. The mixture 'is then poured into suitable molds and allowed to set andharden. The resulting product will be concrete blocks of light Weight and cellular structure.

In contradistinction of the method described in copending application Serial No. 14g-391 no compressed gas :or fair is fused, but -air taken :direct from the atmosphere orgas of ,atmospheric .pressure is utilized -to makethezfoam.

It should be,pointed out that the fiinishedfhlocks are not porous like a sponge; vthat is ,to say, they have no-spaces orcavities-.open at the .surfaces of the blocks through whichewater or moisture-could be absorbed. On thecontrary, the cavities fin the blocks arecellular; thatmeansfclosedoniall sides and-notopen to .the atmosphere.

lIn the .claims .-the -terrn fslurry indicates `,the usual mixture of cement, sand and water, .or their-equivalents ordinarily used in fluidpr :semi-- fluid form in preparation-ofconcrete. .Foani;0r ifoam compound denotes-the compound cornposed and prepared as aboye; 4and cellular concrete denotes Athe .-resultantproductiwith cellular as distinguished from porous consistency.

This vmachine works to'drag :air tinto the slurry and, therefore, *the :motion should be. yvigorous, such that -thespeed maybagreater thanwhenzitfis desired -to gently fmix :ready z-made foam with cement slurry. Y

,Itis to-.beunderstood thatlth'e invention asfhere described may Kbe ,vari-ed considerably as .iso the ingredients'usedzandthesteps ofthe method @within the scope-of the claims. V

.opposite directions, and lastly permitting the 'mixture to harden in suitable molds, said foam compound montainingucasein, water, calcium hydr.ateb.enzoic acid, beta naphthol, and arsenious .ac'idorittheir equivalents in suitable proportions,

,substantially .asl-set .orth.

2. A method of making cellular concrete, consisting iin first rpreparing a slurrry, then separately preparing a foam compound, then driving the foam compound into the slurry by agitation -infopposite directions, .and -lastly ,permitting the mixture to harden .in fsutable molds, -said foam compound containing casein, water, calcium hydrate, henzoic acid, ibeta'naphthol, vand arsenious aoid,or theireguiyalents inthe following proportions,respectively: 100,500, 25, 7,11 and l :parts by fweighmsubstantially .as set forth.

y' 3. A method of making cellular-concrete, consisting in -iirst lpreparing a slurry, then `-separately preparing -a :foam .compound', then driving thefoam compound ,into the slurry -by agitation in .opposite directions, Iand lastly permitting Ithe mixture to .ha-rden ,in vrsuitable molds, said -foarn zcomnound .containing casein, water, calcium hydrate, benzoic acid, beta-naphthoLfand arsenious .acicl, .ortheir equivalents .in the .following proportions, respectively: l100, 500, 25, 7, l jand Al ,aparts by weight; Aof these ingredients the lcasein is .first soaked in ,the Water, together withA the larsenious acid, .until in homogeneous suspension; ,under agitation .the .calcium hydrate is added until the casein is completely dissolved; this mixture vthen permitted to stand -for from fteen ,(15.) ito twenty `,(20) ldays, vwhereupon the benzoic acid and thesloeta naphthol are .dissolved infthe-said mixture, substantially as set forth.

JOHN A. RICE. 

